Rotary jar



Patented Aug. 25, 1936 UNITED STATES ROTARY JAR Sisti Siracusa, Huntington Beach, Calit, assignor to Pacific Shore Investment Corporation, Huntington Beach, Calif., a, corporation of California Application January 23, 1935,v Serial. No. 3.728

5 Claims.

My invention relates to rotary jars, and has particular reference to an improvement of the type of rotary jar disclosed in the copending application of George Walter Bowen, Serial No.

' 744,16? filed September 15, 1934:, for Adjustable rotary jar, which has matured into Patent No. 2,013,127, issued Sept. 3, 1935.

In the drilling and operation of oil wells, i frequently occurs that various tools employed in the well-hole become stuck therein, and, in order todislodge the same, it is necessary to produce an impactupon the tool or upon the: drill string on which the tool is suspended. For this purpose tools have'been devised, known in: the art as jars, those adapted particularly for use in the rotary method of drilling being referred to as rotary jars.

In the copending application of George Walter Bowen, hereinabove referred to, a particular form of rotary jar'is. disclosed, in which the jar comprises essentially a bowl or outer member within which is telescopically assembled a mandrel nor-'- mally connected to the bowl in'a contracted position by means of a friction coupling member which, upon the production of a predetermined longitudinalxstrai'n between the bowl and mandrel will release the mandrel, permitting rapid movement between the bowl and mandrel. until striking abutments' on the bowl and mandrel attract each other, thus producing a blow 01 considerable magnitude directed. upwardly upon the drill string. Since the usual practice is to connect a jar in a drill string during the drilling op-- erations, and to drill with the jar in the drill string, it is necessary that the bowl and mandrel shall: be employed together against relative rotary" movement until it is desired to-produce the jarring impact. Again it is necessary to change the adjustment of the friction coupling device: in order to adjust the tonnage ofthe' blowproduced by the jar and in this application these features are provided for by the employment of splines onthe bowl and mandrel interengaging each other toprevent relative rotary movement between the bowl and mandrel until the mandrel and bowl are moved longitudinally relative to each other to position the splines on the mandrel in line with a space between the splines on the bowl, at which time the mandrel and bowl may be rotated relative to each other, and'by connecting an adjustrately how much relative rotation between the bowl and mandrel will be produced at the jar.

Another object ofv the invention is to provide a rotary jar of the character set iorth which the bowl and mandrel are connected together bymeans of inter-engaging splines in which, when the jar is in extended position a predeterminedtW-ist may be given the drill string which twist will, upon the resetting of the jar to contracted position, cause relative rotary movement between the bowl. and mandrel equal to the twist produced in the'drill string. 7 V e 7 Another object of the invention is to provide a rotary jar of the character set forth, in which the mandrel and bowl are splined together, and in'which the striking abutments on both the bowland the mandrel are formed with uninterrupted annular surfaces, thus increasing the area of contact and i-ncreasingthelifeof the striking abutments. r

. Another object of the invention is to provide, a rotary jar of the character set forth, in which the mandrel and bowt are connected together y means; of splines, the splines on one of said. members being interrupted topermit relative rotary movement; between the bowl and mandrel, in which certain of the splines extend beyondt'he limits of the remainin splines to act as guides, directing the splines into alignment with each other.

Another object of theinventionis to provide a rotary jar of; thecharacter set forth, in which the: bowl, and mandrel are telescopicallyassembled and the diameter of that portion, of the mandrel which extends from the bowl is substantially equal to the exterior diameter of the bowl, and inwhich the change from smaller to larger diameter of themandrel is efiectedby a gradual enlargement of the diameter. 7

Another object of the invention is to provide a jar oil the character set forth, in which passages are provided between the mandrel and the bowl, permitting liquids; to pass therebetween, preventing cushioning of the impact on the jar.-

Other objects and advantages willbe apparent from a stud-y'of-the following specifications, read in connection withthe accompanying drawings, wherein Figure I is a vertical sectional view, taken through a jar constructed in accordance with my invention, illustrating thesame in contracted position;

Fig. 2 is a sectional view, similar to Fig. 1, illustrating the mandrel and jar in their extended or jarring position; Y

Fig. 3' is a view similar to Figs. 1 and 2', illustrating the mandrel and bowl in their-intermediate position ready for relative rotary movement for" adjustment thereof;

Fig. tie a development of the splines employed on the bowl and mandrel of the jar illustrated in Fig. 1;

Figs. 5 and 6 are detailed horizontal sectional views of the bowl and mandrel, respectively, taken along lines V-VI-VVI, of Fig. 1;

Fig. 7 is a detailed horizontal sectional view of the mandrel taken along line VII-VII; and

Fig. 8 is a detailed sectional view of the mandrel and bowl taken along line VIIIVIII of Fig. 1.

Referring to the drawings, I have illustrated herein a jar comprising an outer, or bowl,memher I, the upper end of which is threaded as at 2, to receive the pin 3 of the end of a drill string employed for transmitting rotary drilling forces from a rotary drilling apparatus at the top of the well. Telescopically assembled within the bowl I is a mandrel 4 having an enlarged portion 5 thereof constituting a striking abutment or jarring hammer adapted to strike upon a striking abutment 6 formed upon the interior of the bowl I. ably formed upon a nut 'I screwed into the lower end of the bowl I, as indicated at 8, the upper end of the nut I having an annular face forming the abutment 6 upon which the annular lower surface 9 of the enlargement 5 on the mandrel may strike.

The upper end of the mandrel 4 is illustrated as being formed as a friction head I!) having a plurality of radially extending flanges II formed thereon, these flanges being spaced from each other longitudinally along the friction head II) to constitute interengaging members engaging inwardly extending radial flanges I2 formed upon a friction sleeve or slip I3 so that when the mandrel and bowl are in the contracted position shown in Fig. 1 the flanges I I of the friction head will engage above the flanges I2 on the friction sleeve and the mandrel and bowl will thus be' held in contracted position against relative longitudinal movement until such longitudinal strain is produced between the bowl and mandrel as will cause the flanges II and I2 to slip by each other, at which time the bowl and mandrel will be free to move rapidly to the extended position shown in Fig. 3, bringing the abutment surfaces 9 and 6 of the two members into jarring relation.

As will be understood by those skilled in the art, the friction sleeve I3 is preferably provided with a plurality of outward radially extending flanges I4 spaced longitudinally of the sleeve I3 at points lying between the radial flanges I2 thereof, so that each portion of the sleeve I3 constitutes a bridge-like member permitting the sleeve I3 to spring outwardly when a predetermined longitudinal strain is exerted between the bowl and mandrel. The friction sleeve I3 is preferably tapered upon its outer surface to conform with the tapered bore I5 of the interior of the bowl l so that by moving the friction sleeve I3 upwardly and downwardly relative to the bowl, the amount of longitudinal strain necessary to pass the flanges I I and I2 past each other may be suitably decreased or increased, respectively.

In order to provide for such adjustable movement of the sleeve I3 relative to the bowl, or, more accurately, in order to adjustably limit the distance down the tapered bore l5 to which the sleeve I3 may travel, I provide a supporting ring I6 threaded as at I' I into the interior of the bowl I so that by rotating the ring I6 relative to the bowl I, the ring may be moved upwardly and downwardly in the bowl to thereby adjust the amount of strain which must be placed in the The striking abutment 6 is pre'fe'r-- drill string in order to disengage the friction head I I! from the friction sleeve I3.

In order to permit the bowl and mandrel, when extended, to be reset without requiring the same amount of stress between the members as was required to jar them, the space between the mandrel and bowl immediately above the spring I3 may be sufliciently large to allow the spring sleeve I3 to move upwardly therein away from the tapered bore I5 thus permitting the friction head I and the sleeve I3 to pass each other with the minimum amount of resistance, while a coil spring I8 may be provided bearing upon the upper end of the sleeve I3 to normally seat the friction sleeve I3 tightly in the tapered bore I after the bowl and mandrel have been returned to their contracted position, as shown in Fig. 1.

As stated hereinbefore it is necessary, during the normal operation of a drill string to rotate tools which may be suspended from the drill string, and for this reason it is necessary to provide some means interengaging the bowl and mandrel to permit rotary forces therebetween to drilling tool which may be connected to the extending end I9 of the mandrel 4. For this purpose I'have provided the interior of the bowl I with inwardly extending splines 20 adapted to engage corresponding outwardly extending splines 2| formed upon the mandrel 4 when the bowl and mandrel are'in their contracted position, as shown in Fig. 1.

It will also be observed that the upper end of the mandrel 4 is likewise provided with splines 22 aligned with splines 2I and adapted to engage the bowl splines 20 when the bowl and mandrel are in their extended, or jarring, position, as shown in Fig. 2. Thus when the bowl and mandrel are in either their fully extended position or fully contracted position rotary forces may be transmitted directly between the bowl and the mandrel. However, when the bowl and the mandrel are in their intermediate position, as shown in Fig. 3, the bowl splines 20 will lie in the space between the splines 20 and 22 of the mandrel 4 and at this position rotation of the drill string will rotate the bowl I without correspondingly rotating the mandrel 4. Thus when the'mandrel and bowl are in their intermediate position rotary movement imparted by rotation of the drill string will cause the bowl to be rotated relative to the adjusting ring I6, the ring I6 being provided with splines 23 engaging suitable keyways 24 on the friction'head of the mandrel 4, and in this manner the ring I 6 may be adjusted upwardly and downwardly in the bowl I to vary the strain required to disengage the friction head In and the sleeve I3 and thus vary the tonnage of blow produced when the jar is actuated.

.It will be noted that all of the bowl splines 20 are provided with beveled upper and lower surfaces, as indicated at 20a, to present knife edges to the mandrel splines 2I, 22, thus assisting in guiding the bowl splines into the space between the mandrel splines as the bowl and mandrel are moved either to contracted position or extended position.

It will also be noted that one or-more of the mandrel splines extend beyond the limits of the remaining mandrel splines, the extending splines indicated by the reference characters 2Ia, and 22a constituting guide splines, each having their outer surfaces beveled to engage the beveled surfaces of the bowl splines and guide the mandrel inwardly extending ment when. the: bowl and mandrel are moved to their different. positions. The extending mandrel and bowl splines will, as indicated in Fig. 3,.

provide only a very short distance of travel between the bowl and mandrel free of engagement of the splines and thus when no. rotary torsion is placed in the drill string the mandrel and bowl will be forced to move in direct longitudinal alignment with each other.

However, when it is desired to adjust: the rings l5, exact. and accurate adjustment thereof may be effectively performed by placing a predetermined amount of torsion in the drill string, while the bowl and mandrel are in their extended position, as shown: in Fig. 2, and thus, as soon as the drill string is lowered to reset the jar into contracted position, the torsion will rotate the bowl relative to the mandrel when 'the guide spline 22a just clears the mandrel spline, but, as will be observed. from. an inspection of Fig.3, the total distance between the extending ends of the guide splines Ela and 22a is so minute that the rotary movement permitted the bowl will be only such as will. cause the guide spline 25a: to engage in the next space between the mandrel and splines, thus insuring that the amount of adjustment of the ring IE will be only the space of one spline upon each operation. In the form of the device illustrated therein, there are six splines on the bowl, and six splines on the mandrel. Thus the operator of the rotary table may place one-sixth of a revolution torsion in the drill string when the bowl and mandre'l' are in extended position, and upon lowering the drill string the splines will be moved relative to. each other one space, adjusting. the ring I6 one-sixth of a revolution.

As will be understood by those skilled in the art, the normal operation of the jar would be to merely place a longitudinal strain without torsion in the drill: string operating the jar to pro duce the impact which may be repeated as often as is desired in an effort to dislodge the tool. But if such repeated jarring fails to dislodge the tool the operator may produce accurate impact by successively adjusting the ring [6 by successively placing one-sixth revolution torsion in. the

drill string, as described above, and increase the tonnage blow to the point necessary to dislodge the tool.

By the employment of the guide splines and the pointed or beveled ends on the bowl splines, the operator of the rotary table will be enabled to adjust the ring IS with complete accuracy, since he will know that upon each adjustment operation one-sixth of a revolution adjustment will be produced, and after the tool has been dislodged the operator may then turn the bowl .and mandrel relative to each other back to their original or minimum adjustment position and continue the drilling operations with the jar again set to produce the minimum tonnage of blow.

As will be understood by those skilled in the art, the space between the bowl and mandrel is frequently filled with drilling fluid, mud, and the like, so that the movement of the enlarged head toward the nut 6 upon each jarring operation will force such fluid out of the space between the bowl and the mandrel. The pressure which will be built up in the fluid during its expulsion from the space between the bowl and the mandrel will act as a cushion, absorbing a great portion of the force desired to be produced as an impact in the j'ar.. To overcome this absorption. of the' jarring force, I provideupon the mandrel head 5- aplurality of relatively shallow grooves preferably extending longitudinally of the man drel 51 and spaced between the splines 2i. These grooves 25: provide liquid passages which will permit liquid to be readily passed from the space between. the bowl and mandrel past the headi. Similarly the nut I may be provided with longitudinal shallow grooves 26: communieating with the exterior of the bowl I: so that liquid may readily be forced from the space between the bowl and: mandrel outwardly of the bowl, By employing: the two sets of drilled shallow grooves substantially no. resistance will be builtup any liquid which may lie in the space between the bowl and mandrel and the full. force exerted on: the" drill string will. be transmitted directly between the striking faces 9 and 6.

Again by referring particularly to Fig. 1, it will be observed that the extending end I9 of the mandrel is in the bowl extending below a diameter substantially equal to the exterior diameter of the bowl, while the body portion of the mandrel 4, which lies within the bowl, is of considerably reduceddiameterto permit the formation of a relatively wide striking abutment 6 on: the nut I. If the reduced diameter and enlarged diameter of the mandrel are sharply defined, the: junction of the reduced and large diameters of the mandrel will form the weakest point" along the length of the mandrel and in actual experience it has-been found that this fatigue in the mandrel occurs most rapidly at this point. r The strength and life of the-mandrel may be considerably increased by 'gradually'changing the diameter of the mandrel as by tapering the mandrel outwardly, as indicated at 21', partially tapering the interior of the nut T to con-form with the taper 21 of the mandrel. Thusthe weakness of the mandrel is distributed over a considerable portion of the length of themandrel, providing substantially no pointor line" along which the fatigue may concentrate. r i While r-nave shown and described the preferred' embodiment of my invention, it is to be understood that I do not wish to be limitedto any of the details of construction shown herein, except as defined in the appended claims.

-1 claim? 3 Y 1 In a jarfor use in rotary drilling, a bowlmember and a mandrel member telescopically assembled for longitudinal movement relative to each other from a contracted position to an extended position, striking abutments on said bowl and mandrel members interengageable when said members are) in" extended position, friction means on said bowl and mandrel members. holding said members in contracted position but releasable by the exertion of a predetermined longitudinal strain between said members, means actuated by relative rotation of said bowl and mandrel mem-,

bars for adjusting said friction means to vary the strain required to release it, means interconnecting said bowl and mandrel members against relative rotation when said members are in either said contracted position or said extended position but permitting said relative rotation when said members are in an intermediate position, and guide means on said interconnecting means for guiding said interconnecting means into connecting relation when said members are moved toward either said contracted position or said extended position.

2. In a jar for use in rotary drilling, a bowl member and a mandrel member telescopically assembled for longitudinal movement relative to and mandrel members interengageable when said members are in extended position, friction means on said bowl and mandrel members holding said members in contracted position but releasable by the exertion of a predetermined longitudinal strain between said members, means actuated by relative rotation of said bowl and mandrel members for adjusting said friction means to vary the strain required to release it, means interconnecting said bowl and mandrel members against relative rotation when said members are in either said contracted position or said extended position, but permitting said relative rotation when said members are in an intermediate position, said interconnecting means including a plurality of longitudinally extending splines formed upon one of said members equally spaced circumferentially about said member, one or more cooperating splines formed upon the other of said members engageable in the spaces between said firstnamed splines, one of said last-named splines having a length greater than the remainder thereof to engage in one of said spaces to guide said splines into engagement when said bowl and mandrel members are moved between said contracted position and said extended position.

3. In a jar for use in rotary drilling, a bowl member and a mandrel member telescopically assembled for longitudinal movement relative to each other from a contracted position to an extended position, striking abutments on said bowl and mandrel members interengageable when said members are in extended position, friction means on said bowl and mandrel members holding said members in contracted position but releasable by the exertion of a predetermined longitudinal strain between said members, means actuated by relative rotation of said bowl and mandrel members for adjusting said friction means to vary the strain required to release it, means interconnecting said bowl and mandrel members against relative rotation when said members are in either said contracted position or said extended position but permitting said relative rotation when said members are in an intermediate position, a plurality of longitudinally extending splines formed on said bowl and having a length less than the distance of telescopic movement of said bowl and mandrel members, cooperating splines on said mandrel comprising two groups of splines spaced longitudinally of said mandrel, one of said groups engaging said bowl splines when said mandrel and bowl are in extended position, the other of said groups engaging said bowl splines when said mandrel and bowl are in contracted position, the spacing of said groups being equal to the length of said bowl splines, one or more of said mandrel splines extending into said space between said groups to constitute a guide spline guiding said mandrel and bowl splines into interengaging position.

.4. In a jar for use in rotary drilling, a bowl member and a mandrel member telescopically assembled for longitudinal movement relative to each other from a contracted position to an extended position, striking abutments on said bowl and mandrel members interengageable when said members are in extended position, friction means on said bowl and mandrel members holding said members in contracted position but releasable by the exertion of a predetermined longitudinal strain between said members, means actuated by relative rotation of said bowl and mandrel members for adjusting said friction means to vary the strain required to release it, means interconnecting said bowl and mandrel members against relative rotation when said members are in either said contracted position or said extended position but permitting said relative rotation when said members are in an intermediate position, a plurality of longitudinally extending splines formed on said bowl and having a length less than the distance of telescopic movement of said bowl and mandrel members, cooperating splines on said mandrel comprising two groups of splines spaced longitudinally of said mandrel, one of said groups engaging said bowl splines when said mandrel and bowl are in extended position, the other of said groups engaging said bowl splines when said mandrel and bowl are in contracted position,.the spacing of said groups being equal to the length of said bowl splines, and the ends of. said bowl splines being of reduced area to form guide surfaces guiding said mandrel and bowl splines into interengaging position.

5. In a jar for use in rotary drilling, a bowl member and a mandrel member telescopically assembled for longitudinal movement relative to each other from a contracted position to an extended position, striking abutments on said bowl and mandrel members interengageable when said members are in-extended position, friction means on said bowl and mandrel members holding said members in contracted position but releasable by the exertion of a predetermined longitudinal strain between said members, means actuated by relative rotation of said bowl and mandrel members for adjusting said friction means to vary the strain required to release it, means interconnecting said bowl and mandrel members against relative rotation when said members are in either said contracted position or said extended position but permitting said relative rotation when said members are in an intermediate position, a plurality of longitudinally extending splines formed on said bowl and having a length less than the distance of telescopic movement of said bowl and mandrel members, cooperating splines on said mandrel comprising two groups of splines spaced longitudinally of said mandrel, one of said groups engaging said' bowl splines when said mandrel and bowl are in extended position, the other of said groups engaging said bowl splines when said mandrel and bowl are in contracted position, the spacing of said groups being equal to the length of said bowl splines, and the ends of said bowl splines being of reduced area to form guide surfaces guiding said mandrel and bowl splines into interengaging position, one of said mandrel splines extending into said space between said groups to constitute a guide engaging said bowl splines immediately after separation of said bowl 'and mandrel splines whereby a tortional strain placed upon said mandrel and bowl members will, upon longitudinal relative movement of said members, cause relative rotation of said members equal to the spacing between adjacent bowl splines.

SISTI SIRACUSA. 

